Age-Related Differences in Early Dark Adaptation1

Abstract

The rapid mechanisms of sensitivity regulation following light offset are distinct from the more commonly studied slower form of dark adaptation and are called early dark adaptation (EDA) (Baker, 1953, 1963; Rinalducci, 1967; Geisler, 1983). It is well established that EDA is determined by peripheral retinal mechanisms (Baker, 1973; Baker and Donovan, 1982; Geisler, 1983; Hayhoe, Benimoff, and Hood, 1987). Previous experiments from our laboratory have demonstrated significant alterations in early light adaptation as a function of age (Sturr, Kelly, Kobus and Taub, 1982; Sturr, Church, and Taub, 1985). However, EDA has not yet been investigated in the aging visual system. These early mechanisms of sensitivity regulation may be especially sensitive to age-related changes in vision which would not be revealed by more traditional measures of visual function such as visual acuity. Therefore, the current study evaluated EDA for both young and old observers.